Enhancing Stem Cell Homing

The efficiency with which hematopoietic stem cells (HSC) home to the bone marrow is a critical factor determining clinical outcome in transplantation. Christopherson et al. show that efficiency of stem cell homing can be significantly enhanced by interrupting the activity of a peptidase, CD26, on the donor cell surface. Under normal circumstances, CD26 appears to negatively regulate HSC homing by cleavage of the chemokine CXCL12, thereby preventing binding to its receptor on the surface of HSC. The potential ability to increase the efficiency of HSC homing rather than having to isolate greater numbers of the stem cells may help bone marrow transplantation.